smhowse wrote:There is no part number for the HSR42 unless you buy the Speedster one from Yamaha. Maxair Engineering sells a kit setup that you can buy with the correct cables, tps mod etc. if you don't want to mess with it.
Otherwise just find a Mikuni HSR42 carb, mod it for the tps or add voes and you are good to go.....er so to speak....I'm still working on it

Steven

thanks i looked on ebay and see some different ones, when i looked again and closer it was brackets/ect included for each model. the carbs themselves where the same.

Erbman02 wrote:
Whatta ya mean too late. ever hear of a midnight run? LOL Some of my friends and I do a BCOD ride (butt crack of dawn)lol. we start before the sun rises, head for breakfast, then a ride after.

When I did my "midnight" run the other night my neighbor came over the next day... dunno exactly what he meant about a lawyer and a shotgun.... guess I shouldn't have reved and burned out of the driveway
Also it was 45 degrees

Rode to work this morning little warmer 58degrees and she ran great!! I cannot believe the difference in sound! The throttle response is spot on, no hestitation anymore. The increase in power is awesome! like every performance mod I've done this is a must have!

slothy wrote:smhowse wrote:There is no part number for the HSR42 unless you buy the Speedster one from Yamaha. Maxair Engineering sells a kit setup that you can buy with the correct cables, tps mod etc. if you don't want to mess with it.
Otherwise just find a Mikuni HSR42 carb, mod it for the tps or add voes and you are good to go.....er so to speak....I'm still working on it

Steven

thanks i looked on ebay and see some different ones, when i looked again and closer it was brackets/ect included for each model. the carbs themselves where the same.

The brackets are only for Harley models there is not one made for the R* application (speedster is the exception) so you can just buy a stock Mikuni HSR42 and read the tech article I'm writing and bam instant HP!

smhowse wrote:
Rode to work this morning little warmer 58degrees and she ran great!! I cannot believe the difference in sound! The throttle response is spot on, no hestitation anymore. The increase in power is awesome! like every performance mod I've done this is a must have!

Steven

The tps ohms was so low that the signal to ignition module caused the timeing to be way off. Did you readjust the pilot screw, after the bike was fully warmed? probably will have to adjust idle too since it would be a significant change to pilot screw. usually a tweak to pilot screw idle is still good.

the Yost tube replace the extender tube that the main jet screws into, tho they claim it helps in all ckts from idle to wot, I can't see that happening in the idle ckt due to the vacuum can't pull gas from the main jet. However, what I saw and see is a slightly smoother acceleration from off idle to wot. The tube helps to atomize the gas much more efficiently than the extender tube. I was able to lower my main jet from a 165 to a 160. the better the gas can be atomized when it goes into the piston camber, the better the combustion will be. large drops of gas don't burn. If you go this route, get the one that uses the Mikuni jets, this one does not come with additional jets, uses the same as in stock carb, and there is no tube for stock carb btw. and if you go this route, it appears as if it does not seat all the way down, don't force it, it is that way by design.

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